Whats the best way to redeem a coupon earned in an app without integrating to pos

I would need some clarity around this question, the last part of it doesn't make to much sense. However, the name of the game is seamless flow. Why not figure out the top 5 common pos systems and contact the POS manufacturer. Companies like square offer these type of integration. I'd love to help you sift through this more, so call me to help you get this resolved.

Hello I am Priyanka.
The bottom line is that the answer to your question depends on the type of mobile coupons you want to use. On one side of the spectrum you have static mobile coupons that you can send to subscribers via text message or voice message. People just have to show the text to a person at the store to verify participation in the coupon program. This works great at events or other places where the goal is just as much traffic as possible. No integration with the POS needed.

A second type of mobile coupon, dynamic, distributes a unique code to every single campaign participant. Again, no integration with POS needed, but the ability to track the campaign success improves as coupon codes tracked to individual users can be verified at the point of sale (without being integrated).

https://www.quora.com/How-does-the-technology-that-powers-mobile-coupons-work-is-there-a-need-for-integration-with-the-POS

For further queries you can consult me.

Our firm has dealt with this exact issue building out applications for multiple startups/new ventures that have scaled to hundreds of restaurants (including a great company called TableSavvy). There are a few ways you can achieve this without requiring integration into the POS system. it starts first with identifying what platform/back-end system your app is built on (perhaps something custom or something open source like Magento.) Then you have to look at the payment processor you are utilizing and the current method the restaurants are using to apply discounts/codes. It also depends if the restaurants are booking these customers ahead of time or if they are coming in and redeeming real-time/at any time. Based on my experience you have to limit the amount of time any business manager at the establishment needs to put into the effort in order to keep adoption rates high, but there are some tools you can use to reduce their time to a minimal amount. Happy to connect and hear more about your specific needs and craft a process flow/technical recommendation to fulfill it.